Software Engineering

Jun.-Prof. Dr. Jonathan Immanuel Brachthäuser

Head of the SE research group

Photo of Jonathan Brachthäuser

Jonathan Brachthäuser
Software Engineering
FB Informatik
Universität Tübingen
Sand 13
72076 Tübingen
Germany

Telephone
+49 - (0) 70 71 - 29 - 75491
E-Mail
jonathan.brachthaeuser(at)uni-tuebingen.de
Office
B215
Office hours
by appointment

Publications on Google Scholar Publications on DBLP

SELECTED RESEARCH AREAS

Ergonomic Type- and Effect Systems

Structuring Complex Control Flow

Efficient Compilation

Publications

Other Publications

  • Effects, Capabilities, and Boxes: From Scope-based Reasoning to Type-based Reasoning and Back

    by Jonathan Immanuel Brachthäuser, Philipp Schuster, Edward Lee, and Aleksander Boruch-Gruszecki

    In Proceedings of the International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA), 2022.

  • Type-Level Programming with Match Types

    by Olivier Blanvillain, Jonathan Immanuel Brachthäuser, Maxime Kjaer, and Martin Odersky

    In Proc. ACM Program. Lang. 6(POPL). Association for Computing Machinery, 2022.

  • Region-based Resource Management and Lexical Exception Handlers in Continuation-Passing Style

    by Philipp Schuster, Jonathan Immanuel Brachthäuser, and Klaus Ostermann

    In European Symposium on Programming (ESOP 2022), 2022.

  • A Typed Continuation-Passing Translation for Lexical Effect Handlers

    by Philipp Schuster, Jonathan Immanuel Brachthäuser, Marius Müller, and Klaus Ostermann

    In Proceedings of the International Conference on Programming Language Design and Implementation (PLDI), 2022.

  • What You See Is What You Get: Practical Effect Handlers in Capability-Passing Style

    by Jonathan Immanuel Brachthäuser

    In Ernst Denert Award for Software Engineering 2020. Springer International Publishing, 2022.

Other Publications

  • Back to Direct Style: Typed and Tight

    by Marius Müller, Philipp Schuster, Jonathan Immanuel Brachthäuser, and Klaus Ostermann

    In Proceedings of the International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA), 2023.

  • From Capabilities to Regions: Enabling Efficient Compilation of Lexical Effect Handlers

    by Marius Müller, Philipp Schuster, Jonathan Lindegaard Starup, Klaus Ostermann, and Jonathan Immanuel Brachthäuser

    In Proceedings of the International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA), 2023.

  • With or Without You: Programming with Effect Exclusion

    by Matthew Lutze, Magnus Madsen, Jonathan Immanuel Brachthäuser, and Philipp Schuster

    In Proceedings of the International Conference on Functional Programming (ICFP). ACM Press, 2023.

  • Getting into the Flow: Towards Better Type Error Messages for Constraint-Based Type Inference

    by Ishan Bhanuka, Lionel Parreaux, David Binder, and Jonathan Immanuel Brachthäuser

    In Proceedings of the International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA), 2023.

Other Publications

  • All About That Stack: A Unified Treatment of Regions and Control Effects

    by Philipp Schuster, Jonathan Immanuel Brachthäuser, and Klaus Ostermann

    Technical report. University of Tübingen, Germany, 2021.

  • Tracking Captured Variables in Types

    by Aleksander Boruch-Gruszecki, Jonathan Immanuel Brachthäuser, Edward Lee, Ondrej Lhoták, and Martin Odersky

    In CoRR abs/2105.11896, 2021.

  • Virtual ADTs for Portable Metaprogramming

    by Nicolas Stucki, Jonathan Immanuel Brachthäuser, and Martin Odersky

    In Proceedings of the 18th ACM SIGPLAN International Conference on Managed Programming Languages and Runtimes, pages 36–44. Association for Computing Machinery, 2021.

  • Multi-Stage Programming with Generative and Analytical Macros

    by Nicolas Stucki, Jonathan Immanuel Brachthäuser, and Martin Odersky

    In Proceedings of the 20th ACM SIGPLAN International Conference on Generative Programming: Concepts and Experiences, pages 110–122. Association for Computing Machinery, 2021.

  • Safer Exceptions for Scala

    by Martin Odersky, Aleksander Boruch-Gruszecki, Jonathan Immanuel Brachthäuser, Edward Lee, and Ondřej Lhoták

    In Proceedings of the 12th ACM SIGPLAN International Symposium on Scala, pages 1–11. Association for Computing Machinery, 2021.

  • Representing Monads with Capabilities

    by Jonathan Brachthäuser, Aleksander Boruch-Gruszecki, and Martin Odersky

    Technical report. Higher-Order Programming with Effects (HOPE), 2021.

Other Publications

  • Effekt: Capability-Passing Style for Type- and Effect-Safe, Extensible Effect Handlers in Scala

    by Jonathan Immanuel Brachthäuser, Philipp Schuster, and Klaus Ostermann

    In Journal of Functional Programming 30: , 2020.

  • Compiling Effect Handlers in Capability-Passing Style

    by Philipp Schuster, Jonathan Immanuel Brachthäuser, and Klaus Ostermann

    In Proceedings of the International Conference on Functional Programming (ICFP). ACM Press, 2020.

  • Effect Handlers, Evidently

    by Ningning Xie, Jonathan Immanuel Brachthäuser, Daniel Hillerström, Philipp Schuster, and Daan Leijen

    In Proceedings of the International Conference on Functional Programming (ICFP). ACM Press, 2020.

  • Effekt: Lightweight Effect Polymorphism for Handlers (Technical Report)

    by Jonathan Immanuel Brachthäuser, Philipp Schuster, and Klaus Ostermann

    Technical report. University of Tübingen, Germany, 2020.

  • Effects as Capabilities: Effect Handlers and Lightweight Effect Polymorphism

    by Jonathan Immanuel Brachthäuser, Philipp Schuster, and Klaus Ostermann

    In Proceedings of the International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA). ACM Press, 2020.

  • Design and Implementation of Effect Handlers for Object-Oriented Programming Languages

    by Jonathan Immanuel Brachthäuser

    PhD thesis. University of Tübingen, Germany, 2020.

Other Publications

  • Programming with Implicit Values, Functions, and Control

    by Jonathan Immanuel Brachthäuser and Daan Leijen

    Technical report MSR-TR-2019-7. Microsoft Research, 2019.

  • Zero-cost Effect Handlers by Staging (Technical Report)

    by Philipp Schuster, Jonathan Immanuel Brachthäuser, and Klaus Ostermann

    Technical report. University of Tübingen, Germany, 2019.

Other Publications

Other Publications

  • Towards Naturalistic EDSLs using Algebraic Effects

    by Jonathan Immanuel Brachthäuser

    In Workshop for Domain Specific Languages, Design and Implementation (DSLDI), 2017.

  • Effekt: Extensible Algebraic Effects in Scala (Short Paper)

    by Jonathan Immanuel Brachthäuser and Philipp Schuster

    In Proceedings of the International Symposium on Scala. ACM Press, 2017.

Other Publications

  • Revisiting the Cake Pattern: Scaling "Scalable Component Abstractions"

    by Paolo G. Giarusso and Jonathan Immanuel Brachthäuser

    Technical report. Talk at Scala Symposium 2016, University of Tübingen, Germany, 2016.

  • Prioritizing Regression Tests for Desktop and Web-Applications Based on the Execution Frequency of Modified Code

    by Matthias Hirzel, Jonathan Immanuel Brachthäuser, and Herbert Klaeren

    In Proc. of the Intl. Conference on Principles and Practices of Programming on the Java Platform: Virtual Machines, Languages, and Tools. Association for Computing Machinery, 2016.

  • Parsing with First-Class Derivatives

    by Jonathan Brachthäuser, Tillmann Rendel, and Klaus Ostermann

    In Proceedings of the International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA). ACM Press, 2016.

Other Publications

  • Modularization of Algorithms on Complex Data Structures: An Encoding of Typesafe Extensible Functional Objects

    by Jonathan Immanuel Brachthäuser

    Master thesis. University of Marburg, Germany, 2014.

  • From Object Algebras to Attribute Grammars

    by Tillmann Rendel, Jonathan Immanuel Brachthäuser, and Klaus Ostermann

    In Proceedings of the 2014 ACM International Conference on Object Oriented Programming Systems Languages & Applications (OOPSLA), pages 377–395. ACM Press, 2014.

Curriculum Vitae

Since Nov 2021
Junior Professor

Software Engineering
University of Tübingen

Aug 2020 - Aug 2021
Postdoctoral Researcher

École Polytechnique Fédérale de Lausanne (EPFL), Schweiz
LAMP – Programming Methods Laboratory

Jun 2018 - Aug 2018
PhD Research Internship

Microsoft Research (MSR), Redmond, USA

2014 - 2020
PhD Computer Science

Programming Languages
University of Tübingen

2012 - 2014
MSc. Computer Science

Philipps-Universität, Marburg

2008 - 2012
BSc. Computer Science Media

Hochschule der Medien, Stuttgart

Recent Community Service

OOPSLA 24 (RC), POPL 24 (PC), LMCS 23 (Reviewer), IWACO 23 (PC), Shonan Seminar 203 (Organizer), TOPLAS 23 (Reviewer), OOPSLA 23 (Hybridization Co-Chair), ICFP 23 (PC), CC 23 -- Compiler Construction 23 (PC), TAP 22 -- Transactions on Applied Perception (Reviewer) TOPLAS 22 (Reviewer), SIGPLAN-M 22 Mentoring Program (Mentor), ECOOP 22 (AEC, extended PC), Scala 22 (PC), Hope 22 (PC), PEPM 22 (PC), PLMW @ ICFP 2021 (Mentor), TOPLAS 21 (Reviewer), PLMW @ ICFP 2020 (Mentor), JFP 20 (Reviewer), JFP 19 (Reviewer), Scala 18 (PC), JFP 18 (Reviewer), Scala 17 (Orga), Scala 18-21 (SC)

Assigned Thesis Topics

Frederic Schanne (BSc)

Bridging Theory and Practice: Evaluating Continuation Integration Best Practices at a Software Company

Continuous Integration (CI) is a common best practice in software development. This practice dictates, that among other factors, developers should commit early and often and receive feedback about their work as soon as possible. In order to be effective in a large scale software development environment and to reap all the benefits that come with it, the CI pipeline has to be designed in a certain way and all stakeholders involved need to be instructed.

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Mattis Krauch (BSc)

Partial type signatures for the Effekt language

Partial type signatures are type signatures allowing wildcards in their definition. These wildcards are placeholders for other types which are inferred at compile-time. By using these wildcards, a programmer is able to annotate parts of a type signature manually and let the typer infer the rest. Therefore partial type signatures allow us to omit potentially long and complex parts of a type annotation while providing more restrictions to the type than without any annotation.

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Sina Schäfer (BSc)

Probabilistic Effekt

Inference programming - the adaptation of inference algorithms to a particular model or problem - is difficult in languages that do not deal with side effects or do not handle side effects properly, due to their nature of relying on effectful computation. In functional programming, monad transformers are the most common approach to control side effects. However, this makes it difficult to customise such algorithms. Effects and effect handlers on the other hand introduce another possibility to deal with programmable inference. This thesis will demonstrate this idea by developing three inference patterns (Metropolis-Hastings, particle filtering and guided optimisation) using the language Effekt. The result is a more user-friendly way to adapt and combine parts of these algorithms.

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Dennis Hieber (MSc)

Multiple Return Values in Effekt

Multiple return values in functions have long been regarded as a powerful feature in programming languages, enabling concise and expressive code. However, not all programming languages support this feature natively. Instead, most languages emulate multiple return values only via tuples. In the case of dynamically typed languages like Common Lisp multiple return values are supported but the dynamic handling may cause headaches: (type-of (values x y z)) is the same as (type-of x). This master thesis delves into designing and implementing multiple return values in the Effekt language. The thesis introduces native support for multiple return values in Effekt, exploring their significance and potential impact on software development.

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Maximilian Marschall (BSc)

Is Effekt Fast Yet

Benchmark Effekt based on the “Are we fast yet?” paper.

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Leonard Zieger (BSc)

Spectrum-based fault localization (SBFL) for Haskell

Spectrum-based fault localization (SBFL) is a technique for automatically locating the probable source code location of bugs in software.

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Finished Thesis Topics

Jonas Kräher (BSc)

Software Transactional Memory in Effekt

Concurrent programs are widely used in practice, but notoriously difficult to get right, particularly when dealing with the locking and synchronization of shared memory between threads. However, ensuring correctness becomes even more challenging when individual components, which may function correctly in isolation, interact with each other. Software Transactional Memory offers a solution by abstracting over the low-level details of concurrent programming, providing atomic blocks that enable modular composibility of transactions.

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Matthias Dunkel (BSc)

Reactive: Design and Implementation of a synchronous reactive programming library in Effekt

Reactive systems are an important part of everyday programming. Still, the implementations of such reactive systems differ hugely, which has a major impact on the style and reliability of reactive programs. The main approach to implementing reactivity and parallelism in the industry is to use multi-threading. This approach often leads to non-deterministic behavior. Additionally, programming languages often need extra implementations for reactivity and parallelism to support multi-threading. Languages such as Effekt eradicate the need for additional reactive system language support, by implementing algebraic effects. With algebraic effects, it is possible to implement a vast amount of programs, including reactive systems. In this work, we present Reactive, a library for the programming language Effekt. Reactive uses algebraic effects to implement reactivity and parallelism in direct style. The ability to write programs in direct style leads to more readable code, as it appears to be sequential, while the control flow is handled with algebraic effects. Reactive defines a synchronous execution model, by interleaving waiting parts of the program. The synchronous approach of the library makes decisions over the execution flow of the program deterministic. Parallelism and reactivity are decoupled by using different effects and handlers. With schedulers, Reactive creates the ability to run parts of a program in parallel. Reactive implements different schedulers, which handle the control flow of the program by enforcing rules. Such rules can be the termination of parts of the program when another has already stopped. The awaiting of an event is done by polling an environment in a busy wait loop, which can be interleaved with other parts of the program. Additional to the Effekt implementation, this thesis implements the ability to wait for JavaScript events inside the Effekt language.

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Serkan Muhcu (MSc)

Mutable State in a Language with Effect Handlers

Effekt is a functional programming language developed for research on algebraic effects and handlers. Aside from algebraic handlers, Effekt also features side effects in form of mutable state using region-based memory management. The Effekt compiler has multiple backends, one of which targets the LLVM Intermediate Representation. The LLVM-IR can be compiled to an executable file with many optimization passes on the way. The LLVM backend of Effekt covers only a subset of Effekt’s features. As part of this thesis, we extend the LLVM backend by support for mutable state.

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Franciszek Piszcz (MSc)

Abstract-Interpretation-Based Language Server for Python

Most IDEs for Python development follow traditional code analysis approaches that are known to work well for statically-typed languages such as Java or C++. A lot of modern Python code is untyped, and these conservative tools tend to assign the “Any” type for variables that do not have explicit type annotations. However, programmers are usually able to deduce types (and often concrete values) by looking at surrounding code and jumping through function definitions and call sites.

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David Voigt (BSc)

Resource Finalization for Effect Handlers

Handling resources, such as files or network sockets, in a language with control (such as exceptions) safely can become difficult. We need to make sure that all memory is eventually freed and all file handles and sockets are closed; even in the case of an exception.

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Lukas Stetter (BSc)

Interaktive Lehrbücher

Viele der Lehrmaterialien welche wir in der Lehre verwenden bestehen aus nicht interaktiven Skripten und Foliensätzen. Aber viele Inhalte der Informatik eignen sich besonders gut für eine interaktive Präsentation. Durch eine interaktive Präsentation können auch sehr abstrakte Inhalte greifbar und verständlich gemacht werden. So wird zum Beispiel häufig auf Animationen und interaktive Graphiken zurückgegriffen, um die Ausführung von Algorithmen zu veranschaulichen.

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Pavel Karasik (MSc)

Improving Error Messages with Algebraic Subtyping

Good type errors are an important tool to improve programmer productivity. Ideally, they can help to quickly localize and fix problems and help programmers to not only better understand the error, but also the underlying program.

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Roman Schulte (MSc)

Second-class Modules for the Effekt Programming Language

Effekt is a novel programming language featuring new ways to modularize software and structure complex control flow. In particular, it includes lexical effect handlers as well as an advanced type- and effect system. However, the language is yet lacking a full module system.

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Tim Neumann (BSc)

IDE Support for Lexical Effects and Handlers

Static type systems help to avoid programming errors by indicating to the programmer at compile time that a value potentially has a wrong type. This way, unsupported operations (such as dividing two strings or calling a method on a number) are ruled out before the program is executed.

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News

Three Papers at OOPSLA 2023

Together with our collaborators the SE group presents three different papers at this year’s International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA 2023).

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Paper accepted for publication at OOPSLA 2023

Our paper “From Capabilities to Regions: Enabling Efficient Compilation of Lexical Effect Handlers” (Marius Müller, Philipp Schuster
ResearcherPhilipp Schuster, Jonathan Lindegaard Starup, and Klaus Ostermann, Jonathan Brachthäuser
Head of the SE research groupJonathan Immanuel Brachthäuser) has been accepted for publication at the International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA 2023).

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Teaching Award of the Board of Studies (Studienkommission)

The lecture Programming Languages 2 (Summer Term 2023) conducted by Jonathan Brachthäuser
Head of the SE research groupJonathan Immanuel Brachthäuser, and exercises led by Marcial Gaißert
ResearcherMarcial Gaißert, was honored with the “Teaching Award of the Board of Studies (Studienkommission)”.

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Paper accepted for publication at ICFP 2023

Our paper “With or Without You: Programming with Effect Exclusion” (Matthew Lutze, Magnus Madsen, Philipp Schuster
ResearcherPhilipp Schuster, and Jonathan Brachthäuser
Head of the SE research groupJonathan Immanuel Brachthäuser) has been accepted for publication at the International Conference on Functional Programming (ICFP 2023).

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Paper accepted for publication at OOPSLA 2023

Our paper “Continuation-Passing to Direct Style: Typed and Tight” (Marius Müller, Philipp Schuster
ResearcherPhilipp Schuster, Jonathan Brachthäuser
Head of the SE research groupJonathan Immanuel Brachthäuser, and Klaus Ostermann) has been accepted for publication at the International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA 2023).

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Distinguished Artifact Award (OOPSLA 2022)

The artifact for our paper “Effects, Capabilities, and Boxes: From Scope-based Reasoning to Type-based Reasoning and Back” (Jonathan Brachthäuser
Head of the SE research groupJonathan Immanuel Brachthäuser, Philipp Schuster
ResearcherPhilipp Schuster, Edward Lee, and Aleksander Boruch-Gruszecki) was honored with the Distiguished Artifact Award at the International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA 2023).

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Paper accepted for publication at OOPSLA 2022

Our paper “Effects, Capabilities, and Boxes: From Scope-based Reasoning to Type-based Reasoning and Back” (Jonathan Brachthäuser
Head of the SE research groupJonathan Immanuel Brachthäuser, Philipp Schuster
ResearcherPhilipp Schuster, Edward Lee, and Aleksander Boruch-Gruszecki) has been accepted for publication at the International Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA 2022).

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Paper accepted for publication at PLDI 2022

Our paper “A Typed Continuation-Passing Translation for Lexical Effect Handlers” (Philipp Schuster, Jonathan Brachthäuser
Head of the SE research groupJonathan Immanuel Brachthäuser, Marius Müller, and Klaus Ostermann) has been accepted for publication at the International Conference on Programming Languages, Design, and Implementation (PLDI 2022).

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Paper accepted for publication at ESOP 2022

Our paper “Region-based Resource Management in Continuation-Passing Style” (Philipp Schuster, Jonathan Brachthäuser
Head of the SE research groupJonathan Immanuel Brachthäuser, and Klaus Ostermann) has been accepted for publication at the 31st European Symposium on Programming (ESOP 2022).

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Paper accepted for publication at POPL 2022

Our paper “Type-Level Programming with Match Types” (Olivier Blanvillain, Jonathan Brachthäuser
Head of the SE research groupJonathan Immanuel Brachthäuser, Maxime Kjaer, and Martin Odersky) has been accepted for publication at the ACM SIGPLAN Symposium on Principles of Programming Languages (POPL 2022).

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Best Paper Award – GPCE 2021

Our paper Multi-Stage Programming with Generative and Analytical Macros, by Nicolas Stucki, Jonathan Brachthäuser
Head of the SE research groupJonathan Immanuel Brachthäuser, and Martin Odersky was honored with the Best Paper Award at the International Conference on Generative Programming: Concepts & Experiences (GPCE 2021)

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